The product of first five terms of a G.P. with first term a and common ratio r > 1 is equal to :

1. $\dfrac{a(r^5 - 1)}{r - 1}$

2. ar⁴

3. a⁵r¹⁰

4. $\dfrac{a(r^5 - 1)}{r}$

If 5th, 8th and 11th terms of a G.P. are x, y and z respectively, then which one of the following is correct?

1. y² = x²z²

2. y² = x² + z²

3. y² = xz

4. xyz = 1

Assertion (A): The nth term of a G.P. is given by T_n = ar^{n − 1}.

Reason (R): A sequence a₁, a₂, a₃, ……. is said to be a G.P. if $\dfrac{a$1}{a2} = \dfrac{a2}{a3} = \dfrac{a3}{a4} = constant known as the common ratio.

1. Both A and R are true, and R is the correct explanation of A.

2. Both A and R are true, but R is not the correct explanation of A.

3. A is true, but R is false.

4. A is false, but R is true.

Assertion (A): The 50th term from the end of the G.P. 4, 6, 9, $\dfrac{27}{2}, ……\dfrac{6561}{64}$ is $\dfrac{27}{2}$.

Reason (R): nth term from the end of a G.P. is given by $\dfrac{l}{r^{n-1}}$.

1. Both A and R are true, and R is the correct explanation of A.

2. Both A and R are true, but R is not the correct explanation of A.

3. A is true, but R is false.

4. A is false, but R is true.